1. Field of the Invention
The present invention relates to a recording apparatus comprising an ink jet recording head mounted on a carriage and serving to discharge an ink drop corresponding to print data, and a wiping device for slidably coming in contact with the nozzle forming surface of the recording head to remove waste ink, and more particularly to a recording apparatus comprising a wiper cleaner for cleaning the waste ink sticking to a wiping device and a cleaning control method for wiping device in the apparatus.
2. Description of Related Art
An ink jet recording apparatus generally comprises an ink jet recording head for receiving the supply of an ink from an ink cartridge and paper feeding means for relatively moving a recording paper to the recording head, and recording is carried out by discharging an ink drop to the recording paper based on print data while moving the recording head. The recording head capable of discharging each ink such as black, yellow, cyan or magenta is mounted on a carriage, and full color print can be carried out by changing the discharge ratio of each color ink in addition to text print using a black ink.
The ink jet recording head has a problem in that since an ink pressurized in a pressure generating chamber is discharged as an ink drop to a recording paper from a nozzle to carry out printing, a printing failure is caused on the function of discharging the ink from a nozzle opening because an ink viscosity is increased, the ink is caked, a dust sticks, and furthermore, a bubble is mixed due to the evaporation of a solvent from the nozzle opening.
For this reason, the recording apparatus of this kind comprises a capping device for sealing the nozzle forming surface of a recording head during non-printing. The capping device functions as a cover member for preventing the ink of the nozzle opening in the recording head from being dried, and furthermore, has the function of sealing the nozzle forming surface by the capping device and sucking the ink from the nozzle opening by a negative pressure applied from a sucking pump, thereby eliminating the clogging state of the nozzle opening if the nozzle opening is clogged.
A process for forcibly sucking and discharging an ink which is to be carried out for eliminating the clogging state of the recording head is referred to as a cleaning operation and is executed when the printing is restarted after the apparatus is stopped for a long time or when a user recognizes a printing failure to operate a cleaning switch, for example. According to the cleaning operation, a negative pressure is applied through a sucking pump and the ink is sucked and discharged from the recording head into the capping device, and an operation for sweeping and cleaning the nozzle forming surface is then carried out by means of a wiping member formed by a rubber material, for example.
The wiping device fulfils the function of scraping a waste ink sticking to the nozzle forming surface and cleaning the nozzle forming surface with the cleaning operation, and functions to scrape a paper dust or other dusts in addition to the waste ink when the wiping member slidably comes in contact with the nozzle forming surface. Due to the repetition of the wiping operation, accordingly, the wiping member has a problem in that the waste ink is accumulated and is scattered in a comparatively large amount into the apparatus by the return function of the wiping member immediately after the wiping member goes away from the nozzle forming surface with the wiping operation.
Moreover, the waste ink sticking to the wiping member flows down along the wiping member according to gravity. Therefore, in the case in which the inside of the recording apparatus is contaminated widely by the waste ink freely flowing down from the wiping member and reaches a driving mechanism, the normal printing operation of the apparatus is blocked.
On the other hand, the waste ink sticking to the wiping member is thickened or coagulated over the wiping member with the evaporation of the solvent. In the case in which the wiping operation is carried out again in this state, the thickened substance or the coagulated substance enters a fine nozzle opening on the nozzle forming surface so that the ink drop is discharged from the nozzle opening with difficulty and a printing failure referred to as so-called dot missing is generated.
It can also be proposed that means for removing the waste ink sticking to the wiping member is removed. This means is to prevent the waste ink from being scattered when the waste ink sticking to the wiping member is to be removed.
The invention has been made to solve the problems and has an object to provide an ink jet recording apparatus capable of suppressing the generation of the printing failure and reducing the degree of contamination in the recording apparatus which is caused by the waste ink.
In order to attain the object, the invention provides an ink jet recording apparatus comprising an ink jet recording head mounted on a carriage capable of being reciprocated and serving to discharge an ink drop corresponding to print data, a capping device capable of sealing a nozzle forming surface of the recording head and sucking and discharging an ink from the recording head upon receipt of a negative pressure from a sucking pump, and a wiping device capable of cleaning the nozzle forming surface in slidable contact with the nozzle forming surface of the recording head, wherein the wiping device is constituted such that it can advance to and retreat from a moving path for the recording head, and there is provided a wiper cleaner for abutting on the wiping device and moving in a plane direction of the wiping device with advance and retreat operations of the wiping device, there by removing a waste ink sticking to the wiping device.
In this case, it is preferable that the wiper cleaner should be provided on a print region side in the capping device. On the other hand, it is preferable that the wiping device should be constituted such that it can advance and retreat in a direction orthogonal to the nozzle forming surface of the recording head with respect to the moving path for the recording head and receives the abutment of the wiper cleaner when retreating from the moving path for the recording head.
Moreover, it is desirable that the wiper cleaner should be constituted by an elastic material. In addition, it is desirable that the wiper cleaner should be constituted by a material capable of absorbing the waste ink.
In a preferred embodiment, the wiper cleaner is formed in the capping device and is molded integrally with a cap member capable of carrying out sealing in abutment on the nozzle forming surface of the recording head. In another preferred embodiment, moreover, a concave portion constituting a box-shaped space is formed between a cap member formed in the capping device and capable of carrying out sealing in abutment on the nozzle forming surface of the recording head and the wiper cleaner provided in the capping device, and a through hole is formed in a lower bottom part of the concave portion and a discharge pipe is protruded downward to surround the through hole.
In a further preferred embodiment, moreover, the capping device is provided with a housing portion of the wiper cleaner constituting a box-shaped space portion on the print region side and a part of the wiper cleaner accommodated in the housing portion is protruded in a horizontal direction such that it can abut on the wiping device. Also in this case, it is preferable that a through hole should be formed in a lower bottom part of the housing portion and a discharge pipe should be protruded downward to surround the through hole.
The wiping device is so constituted as to advance and retreat in a horizontal direction perpendicular to the moving path for the recording head. In this case, it is desirable that the wiper cleaner should be provided in the vicinity of an advance and retreat path for the wiping device. Furthermore, it is desirable that the wiper cleaner should be provided on a frame of the sucking pump.
Moreover, a driving mechanism of the wiping device can also employ such a structure as to include a cam mechanism having a pump driving shaft for driving the sucking pump and a gear device to be driven by a rotation of the pump driving shaft. In this case, it is desirable that the driving mechanism should be constituted by a driving mechanism for applying, to the wiping device, such driving force as to advance to the moving path by a rotation in a sucking direction of the pump driving shaft and to retreat from the moving path by a rotation in an opposite direction to the sucking direction.
On the other hand, the invention provides a cleaning control method for a wiping member in an ink jet recording apparatus comprising an ink jet recording head mounted on a carriage capable of being reciprocated and serving to discharge an ink drop corresponding to print data, a capping device capable of sealing a nozzle forming surface of the recording head and sucking and discharging an ink from the recording head upon receipt of a negative pressure from a sucking pump, and a wiping device capable of cleaning the nozzle forming surface in slidable contact with the nozzle forming surface of the recording head, comprising the steps of causing the wiping device to advance to a moving path for the recording head into a wiper set state with the nozzle forming surface of the recording head sealed by the capping device, causing a wiper cleaner provided in the capping device to abut on the wiping device in the set state with the nozzle forming surface of the recording head unsealed from the capping device, causing the wiping device to slidably come in contact with the nozzle forming surface with a movement of the recording head toward a print region side, and causing the wiping device to retreat from the moving path for the recording head with the wiper cleaner abutting on the wiping device, and removing a waste ink sticking to the wiping device through the wiper cleaner.
In this case, in such a condition that the nozzle forming surface of the recording head is sealed by the capping device, a cleaning operation for applying a negative pressure into the capping device through the sucking pump to suck and discharge an ink from the recording head is carried out.
According to the ink jet recording apparatus employing the cleaning control method for the wiping member, the wiping device is constituted to advance to and retreat from the moving path for the recording head and the wiper cleaner is caused to abut on the wiping device in the set state in which the wiping device advances. When the wiping device is to brought into the reset state in which it retreats from the moving path for the recording head, the waste ink sticking to the wiping device is wiped away through the wiper cleaner and the wiping device is cleaned. At this time, the wiper cleaner is relatively moved in the plane direction of the wiping device. Therefore, the waste ink sticking to the wiping device can be prevented from being scattered.
In this case, the recording head is sealed by the capping device and the wiping device is caused to advance to the moving path for the recording head and is brought into the set state during or immediately after the execution of the cleaning operation for sucking and discharging the ink from the recording head by a negative pressure. On the other hand, the wiper cleaner is provided on the print region side in the capping device. Consequently, when the capping state of the recording head is released, the wiper cleaner can be caused to abut on the wiping device with the movement of the capping device.
By the movement of the recording head to the print region side, the nozzle forming surface can be wiped through the wiping device in the set state. Subsequently, the wiper cleaner is caused to retreat from the moving path for the recording head and is brought into the reset state so that the waste ink sticking to the wiping device can be removed by the wiper cleaner. Accordingly, the waste ink sticking to the wiping device can be cleaned away for each execution of the cleaning operation. In addition, the wiper cleaner is relatively moved in the plane direction of the wiping device. Therefore, it is possible to prevent the waste ink sticking to the wiping device from being scattered and to wipe the waste ink away.
Therefore, it is possible to effectively prevent such a problem that the thickened substance enters the fine nozzle opening on the nozzle forming surface to discharge the ink drop from the nozzle opening with difficulty when the waste ink sticking to the wiping device is thickened and the wiping operation is carried out again.
Moreover, the waste liquid ink sticking to the wiping device is wiped away by means of the wiper cleaner for each execution of the cleaning operation. Therefore, immediately after the wiping operation is ended, the degree of scatter of the waste ink into the apparatus can also be reduced by the return function of the wiping member. Furthermore, a countermeasure for collecting and dropping the waste ink wiped away by the wiper cleaner is taken as will be described below. Consequently, it is possible to effectively reduce contamination in equipment due to the waste ink and to guarantee the normal print operation of the apparatus for a long period of time.